1) Schematic. You can export the OrCAD schematic to EDIF format and import the EDIF file in DipTrace Schematic.
2) PCB Layout. If you use the old OrCAD Layout you can save the board to the OrCAD Min Interchange file and import the MIN file in DipTrace PCB Layout.
3) Libraries. You can export to OrCAD XML, and use the below tool to convert to a KiCAD XML. DipTrace imports KiCAD libraries. Https://github.com/fjullien/orlib2ki